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S Dresel

Publications and source records attributed to S Dresel.

At least 19 recordsLinked to original sources
PubMed2007

Impact of patient- and disease-specific factors on SLNB in breast cancer patients. Are current guidelines justified?

BACKGROUND: The evidence on which to base guidelines for sentinel lymph node biopsy (SLNB) in breast cancer is still limited. In order to facilitate the further implementation of renewed guidelines, we evaluated patient- and disease-specific factors for their impact on the results of SLNB. MATERIALS AND METHODS: Prospective data acquisition from patients undergoing surgery for primary invasive breast cancer was performed. All patients underwent SLNB using the radiocolloid or the combined technique. The association of patient- and disease-specific factors to detection rate and false-negative rate was calculated using univariate and multivariate analyses (P < 0.05 considered as significant). Calculation of the false-negative rate was based on patients who underwent a backup axillary dissection. RESULTS: Among 455 consecutively enrolled patients, a significant inverse association to the detection rate was found for extracapsular extension of non-SLN metastases, body mass index (BMI), number of involved lymph nodes, pT category, tumor size, and age. A significant association to the false-negative rate to identify macrometastases was found for pT category, tumor size, and grading. Other factors, such as prior surgery, multicentric tumor growth, or vascular invasion, showed no influence. A cut-point analysis revealed that a tumor size of 2 cm separated the collective of patients with the highest significance in regard to the false-negative rate (9% vs. 25%). CONCLUSION: Our results indicate that SLNB can be safely used in elderly and obese patients with multicentric tumors and those having undergone prior surgery for benign breast disease. However, the method should be applied with caution in patients with tumors larger than 2 cm.

Adult↗
PubMed2005

Striatal dopamine transporter availability is associated with the productive psychotic state in first episode, drug-naive schizophrenic patients.

OBJECTIVE: Supposing a "hyperdopaminergic State" associated at least with acute psychotic illness phases in schizophrenia, a direct relationship between striatal dopamine metabolism and the core psychopathological symptoms rarely can be provided. Recently, a new SPECT ligand to the presynaptic dopamine transporter (DAT) was introduced. Association of DAT availability and the acute psychotic syndrome is now demonstrated in a large cohort of first episode, never treated schizophrenic patients. METHODS: Twenty-eight inpatients suffering from a first acute exacerbation of schizophrenia and 12 healthy control subjects underwent SPECT scanning with the new radioligand [(99m)Tc]TRODAT-1. On the day of SPECT, psychopathology was assessed using specific scales including PANSS. RESULTS: There was no significant difference in [(99m)Tc]TRODAT-1 specific binding to the striatal DAT comparing both groups. The extend of hallucinations was significantly inversely correlated with DAT availability in patients with a predominantly positive syndrome type. DISCUSSION: Our data support evidence that differences in presynaptic dopaminergic activity in schizophrenic patients are associated with the extend of the acute psychotic syndrome. [(99m)Tc]TRODAT-1 seems to be a useful agent for in vivo assessment of a psychopathological association with dopamine metabolism.

Acute Disease↗
PubMed2005

The striatal dopamine transporter in first-episode, drug-naive schizophrenic patients: evaluation by the new SPECT-ligand[99mTc]TRODAT-1.

Following the current hypothesis that acute schizophrenic psychotic illness is associated with a striatal 'hyperdopaminergic state', presynaptic integrity and dopamine transporter (DAT) density in first-episode, neuroleptic-naive schizophrenic patients was measured by single-photon-emission-tomography (SPECT) and compared with that in healthy control subjects. A new SPECT-ligand for assessment of the striatal DAT, the Technetium-99m-labelled tropane TRODAT-1 ([99mTc]TRODAT-1), was used. Ten inpatients suffering from a first acute schizophrenic episode and 10 age- and sex-matched healthy control subjects underwent SPECT with [99mTc]TRODAT-1. On the day of SPECT, psychopathological ratings were performed with the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS) and Schedule for Assessment of Negative Symptoms (SANS). Patients had not previously received any neuroleptic or antidepressant medication. Mean specific TRODAT-1 binding in the striatum did not differ significantly between the patient and the age- and sex-matched control group (1.25 vs. 1.28). Variance was significantly higher in the patient group. The data obtained with the new ligand in first-episode, drug-naive schizophrenic patients are in line with the PET results from the group of Laakso et al. in a comparable patient sample. [99mTc]TRODAT-1 seems to be a valuable new SPECT-ligand in the evaluation of the presynaptic site of the striatal dopaminergic synapse in schizophrenia.

Acute Disease↗
PubMed2004

Colorectal cancer patients before resection of hepatic metastases. Impact of (18)F-FDG PET on detecting extrahepatic disease.

AIM: Evaluation of the role of FDG-PET in comparison to conventional staging methods for detecting extrahepatic tumour deposits prior to resection of liver metastases. PATIENTS, METHODS: In our prospective study, 58 patients (24 women, 34 men; age 33-81 years) with liver metastases of colorectal carcinoma underwent FDG-PET. Images were acquired in 3D-mode including transmission scans and reconstructed iteratively. For conventional staging all patients underwent abdominal ultrasound, helical computed tomography (CT) of the thorax and abdomen, and colonoscopy/rectoscopy. A preliminary therapeutic decision was established without knowledge of the FDG-PET findings. Thereafter, it was revised or confirmed according to the results of FDG-PET. RESULTS: In 3/58 patients extrahepatic tumour deposits were concordantly identified with both conventional staging methods and FDG-PET. However, in one case, both conventional methods and FDG-PET were false positive regarding pulmonary metastases. In 12/58 patients, nothing but FDG-PET detected extrahepatic tumour masses, which were later confirmed either by histology or follow-up. CONCLUSION: Our study suggests that in 21% of patients exclusively FDG-PET is an appropriate diagnostic tool to reveal extrahepatic metastases or local recurrence of colorectal carcinoma. Our results demonstrate that FDG-PET provides relevant additional information for accurate therapeutic planning as compared to the conventional combination of staging methods. Therefore, FDG-PET has to exert a decisive influence on the decision for resection of hepatic metastases.

Adult↗
PubMed2003

[18F]FDG imaging of head and neck tumours: comparison of hybrid PET and morphological methods.

The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose ([(18)F]FDG) imaging of head and neck tumours using a second- or third-generation hybrid PET device. Results were compared with the findings of spiral computed tomography (CT) and magnetic resonance imaging (MRI), and, as regards lymph node metastasis, the ultrasound findings. A total of 116 patients with head and neck tumours (83 males and 33 females aged 27-88 years) were examined using a hybrid PET scanner after injection of 185-350 MBq of [(18)F]FDG (Picker Prism 2000 XP-PCD, Marconi Axis gamma-PET(2) AZ). Hybrid PET examinations were performed in list mode using an axial filter. Reconstruction of data was performed iteratively. Ninety-six patients underwent CT using a multislice technique (Siemens Somatom Plus 4, Marconi MX 8000), 18 patients underwent MRI and 100 patients were examined by ultrasound. All findings were verified by histology, which was considered the gold standard, or, in the event of negative histology, by follow-up. Correct diagnosis of the primary or recurrent lesion was made in 73 of 85 patients using the hybrid PET scanner, in 50 of 76 patients on CT and in 7 of 10 patients on MRI. Hybrid PET successfully visualised metastatic disease in cervical lymph nodes in 28 of 34 patients, while 23 of 31 were correctly diagnosed with CT, 3 of 4 with MRI and 30 of 33 with ultrasound. False positive results regarding lymph node metastasis were seen in three patients with hybrid PET, in 14 patients with CT and in 13 patients with ultrasound. MRI yielded no false positive results concerning lymph node metastasis. In one patient, unrecognised metastatic lesions were seen on hybrid PET elsewhere in the body (lung: n=1; bone: n=1). Additional malignant lesions at sites other than the head and neck tumour were found in three patients (one patient with lung cancer, one patient with pelvic metastasis due to a carcinoma of the prostate and one patient with pulmonary metastasis due to breast cancer). It is concluded that [(18)F]FDG PET with hybrid PET scanners is superior to CT and MRI in the diagnosis of primary or recurrent lesions as well as in the assessment of lymph node involvement, whereas it is inferior to ultrasound in the detection of cervical lymph node metastasis.

Adult↗
PubMed2003

Staging of recurrent and advanced lung cancer with 18F-FDG PET in a coincidence technique (hybrid PET).

The aim of this study was to evaluate [18F]fluorodeoxyglucose ( F-FDG) imaging of recurrent or inoperable lung cancer using a hybrid positron emission tomography (PET) device of the third generation. Examinations were compared with the results of conventional staging. Thirty-six patients suffering from recurrent or primarily inoperable lung cancer (29 men, seven women; age 64.8+/-12.0 years) were examined using hybrid PET (Marconi Axis gamma-PET ) 60 min after injection of 370 MBq F-FDG. The data obtained were reconstructed iteratively. All patients received a computed tomography (CT) scan using either the spiral or multislice technique. All lesions suspicious for primary or recurrent tumour were verified by biopsy; mediastinal lymph nodes were considered as malignant, when positive histology or a small axis diameter of greater than 1 cm measured with CT in addition to progression of clinical course was found. Distant metastases were diagnosed by CT and bone scintigraphy. Using hybrid PET all lesions showed a focally elevated glucose metabolism. Lymph node involvement of the ipsilateral peribronchial and hilar station (N1) was identified in 24/26 cases (92%), in 26/29 cases (90%) of ipsilateral central manifestation (N2) and in 11/13 (85%) cases of central contralateral or supraclavicular lymphatic infestation (N3). Pulmonary spread in hybrid PET was found in 4/8 cases (50%), whereas mainly lung metastases with a diameter of 1.5 cm and smaller were missed. Pleural involvement diagnosed by CT was verified in 4/5 patients. All four patients with bony metastases in conventional staging also presented with positive findings in hybrid PET (8/9 lesions). Concordance with conventional staging was found in 28/36 of patients (78%). In 4/36 patients (11%) unknown sites of tumour were detected leading to therapeutic consequences in three patients after radiological confirmation. Hybrid PET would have led to an understaging in four cases (11%), resulting theoretically in inefficient treatment in two patients. Hybrid PET for F-FDG imaging in the staging of recurrent or primarily inoperable lung cancer supplied equal (78%) or more information (11%) compared to conventional staging procedures. Using the information of hybrid PET alone, 11% of the patients would have been understaged. We conclude that hybrid PET has the potential for use as an additional staging tool in this subgroup of patients, providing supplementary information compared to conventional staging modalities.

Adenocarcinoma↗
PubMed2002

Striatal dopamine D2 receptor binding of risperidone in schizophrenic patients as assessed by 123I-iodobenzamide SPECT: a comparative study with olanzapine.

The aim of this investigation was to compare the degree of striatal dopamine-(D2) receptor blockade by two atypical antipsychotic drugs, risperidone and olanzapine. The percentage of D2 receptor occupancy during treatment was calculated by comparing the results of 123I-iodobenzamide SPECT with those from healthy control subjects. Twenty inpatients suffering from schizophrenia or schizoaffective psychosis according to DSM IV/ICD-10 criteria were treated with clinically recommended doses of risperidone and compared with 13 inpatients treated with up to 20 mg olanzapine. Neuroleptic dose and D2 receptor blockade correlated strongly for both risperidone (Pearson r = -0.86, p = 0.0001) and olanzapine (Pearson r = -0.77, p = 0.002). There was no significant difference between the D2 receptor occupancy of the two substances when given in the clinically recommended dose range (unpaired t-test, t = -0.112, p = 0.911).

Adult↗
PubMed2002

[Diagnosis of initial changes in the hand of patients with rheumatoid arthritis--comparison between low-field magnetic resonance imaging, 3-phase bone scintigraphy and conventional x-ray].

UNLABELLED: Besides conventional X-rays, in the diagnostic work up of initial changes in patients suffering from rheumatoid arthritis (RA), 3-phase bone scintigraphy (3P-Sz) is as well established as magnetic resonance imaging (MRI). The aim of this study was to compare the diagnostic value of the newly developed low field MRI with the proven methods X-rays and 3P-Sz. METHODS: 65 patients (47f, 18m; 20-86 yrs) were studied on a one day protocol with 3P-Sz (550 MBq Tc-99m DPD), MRI and X-rays of the hands. Images were visually analysed by two blinded nuclear medicine physicians and radiologists and classified as a) RA-typical, b) inflammatory, non-RA-typical and c) non inflammatory changes. All methods were compared to 3P-Sz as golden standard. RESULTS: In comparison to 3P-Sz, low field MRI presents with almost equal sensitivity and specificity in rheumatoid-typical and inflammatory changes. Conventional X-rays revealed in arthritis-typical changes as well as in inflammatory changes a significantly lower sensitivity and also a lower negative predictive value while specificity equals the one of MRI. Quantitative analysis of 3P-Sz using ROI-technique unveiled significantly higher values in patients with rheumatoid arthritis than in those with no inflammatory changes. CONCLUSION: MRI represents an equally sensitive method in the initial diagnosis of rheumatoid-typical and inflammatory changes in the region of the hands as compared to the 3P-Sz. Besides the basic diagnosis with conventional X-rays, 3P-Sz is still the recommended method of choice to evaluate the whole body when RA is suspected. Additionally, quantitative analysis of the 3P-Sz using the ROI technique in the region of the hands reveals statistically significant results and should therefore be taken into account in the assessment of inflammatory changes.

Adult↗
PubMed2001

Comparison of in vivo dopamine D2 receptor binding of [(123)I]AIBZM and [(123)I]IBZM in rat brain.

[(123)I]AIBZM, (S)-5-[(123)I]-Iodo-N-[(1-ethyl-2-pyrrolidinyl)]methyl-4-amine-2-methoxybenzamide is a derivative with high affinity for the D2 receptor. Labeling was achieved by the Iodogen method. The in vivo affinity for the D2 receptor and the biological characteristics were performed in rats. The brain uptake of [(123)I]AIBZM was significantly lower, however the striatum/cerebellum ratio (2h p.i.) was higher than that of [(123)I]IBZM. Because of the high affinity and its possibly lower unspecific binding compared to [(123)I]IBZM, [(123)I]AIBZM may be a potential imaging agent for the D2 dopamine receptor.

Animals↗
PubMed2001

[Calculation of the partial function of the kidney with DMSA in pediatrics: is the evaluation of the geometric mean necessary?].

UNLABELLED: For assessment of differential renal function (PF) by means of static renal scintigraphy with Tc-99m-dimercaptosuccinic acid (DMSA) the calculation of the geometric mean of counts from the anterior and posterior view is recommended. AIM: Of this retrospective study was to find out, if the anterior view is necessary to receive an accurate differential renal function by calculating the geometric mean compared to calculating PF using the counts of the posterior view only. METHODS: 164 DMSA-scans of 151 children (86 f, 65 m) aged 16 d to 16 a (4.7 +/- 3.9 a) were reviewed. The scans were performed using a dual head gamma camera (Picker Prism 2000 XP, low energy ultra high resolution collimator, matrix 256 x 256, 300 kcts/view, Zoom: 1.6-2.0). Background corrected values from both kidneys anterior and posterior were obtained. Using region of interest technique PF was calculated using the counts of the dorsal view and compared with the calculated geometric mean [SQR(Ctsdors x Ctsventr)]. RESULTS: The differential function of the right kidney was significantly less when compared to the calculation of the geometric mean (p < 0.01). The mean difference between the PFgeom and the PFdors was 1.5 +/- 1.4%. A difference > or = 5% (5.0-9.5%) was obtained in only 6/164 scans (3.7%). Three of 6 patients presented with an underestimated PFdors due to dystopic kidneys on the left side in 2 patients and on the right side in one patient. The other 3 patients with a difference > 5% did not show any renal abnormality. CONCLUSION: The calculation of the PF from the posterior view only will give an underestimated value of the right kidney compared to the calculation of the geometric mean. This effect is not relevant for the calculation of the differential renal function in orthotopic kidneys, so that in these cases the anterior view is not necessary. However, geometric mean calculation to obtain reliable values for differential renal function should be applied in cases with an obvious anatomical abnormality.

Adolescent↗
PubMed2001

[[F-18]FDG imaging of head and neck tumors: comparison of hybrid PET, dedicated PET and CT].

AIM: Aim of the study was to evaluate [F-18]FDG imaging of head and neck tumors using a Hybrid-PET device of the 2nd or 3rd generation. Examinations were compared to dedicated PET and Spiral-CT. METHODS: 54 patients suffering from head and neck tumors were examined using dedicated PET and Hybrid-PET after injection of 185-350 MBq [F-18]FDG. Examinations were carried out on the dedicated PET first followed by a scan on the Hybrid-PET. Dedicated PET was acquired in 3D mode, Hybrid-PET was performed in list mode using an axial filter. Reconstruction of data was performed iteratively on both, dedicated PET and Hybrid-PET. All patients received a CT scan in multislice technique. All finding have been verified by the goldstandard histology or in case of negative histology by follow up. RESULTS: Using dedicated PET the primary or recurrent lesion was correctly diagnosed in 47/48 patients, using Hybrid-PET in 46/48 patients and using CT in 25/48 patients. Metastatic disease in cervical lymph nodes was diagnosed in 17/18 patients with dedicated PET, in 16/18 patients with Hybrid-PET and in 15/18 with CT. False positive results with regard to lymph node metastasis were seen with one patient for dedicated PET and Hybrid-PET, respectively, and with 18 patients for CT. In a total of 11 patients unknown metastatic lesions were seen with dedicated PET and with Hybrid-PET elsewhere in the body. Additional malignant disease other than the head and neck tumor was found in 4 patients. CONCLUSION: Using Hybrid-PET for [F-18]FDG imaging reveals a loss of sensitivity and specificity of about 1-5% as compared to dedicated PET in head and neck tumors. [F-18]FDG PET with both, dedicated PET and Hybrid-PET is superior to CT in the diagnosis of primary or recurrent lesions as well as in the assessment of lymph node involvement.

Adult↗
PubMed2000

Attention deficit hyperactivity disorder: binding of [99mTc]TRODAT-1 to the dopamine transporter before and after methylphenidate treatment.

Involvement of the dopaminergic system has been suggested in patients suffering from attention deficit hyperactivity disorder (ADHD) since the symptoms can be successfully treated with methylphenidate, a potent blocker of the dopamine transporter (DAT). This study reports the findings on the status of the DAT in adults with ADHD before and after commencement of treatment with methylphenidate, as measured using [99mTc]TRODAT-1. Seventeen patients (seven males, ten females, aged 21-64 years, mean 38 years) were examined before and after the initiation of methylphenidate treatment (3x5 mg/day). All subjects were injected with 800 MBq [99mTc]TRODAT-1 and imaged 3 h p.i. Single-photon emission tomography (SPET) scans were acquired using a triple-headed gamma camera. For semiquantitative evaluation of the DAT, transverse slices corrected for attenuation were used to calculate specific binding in the striatum, with the cerebellum used as background [(STR-BKG)/BKG]. Data were compared with an age-matched control group. It was found that untreated patients presented with a significantly increased specific binding of [99mTc]TRODAT-1 to the DAT as compared with normal controls [(STR-BKG)/BKG: 1.43+/-0.18 vs 1.22+/-0.06, P<0.001]. Under treatment with methylphenidate, specific binding decreased significantly in all patients [(STR-BKG)/BKG: 1.00+/-0.14, P<0.001]. Our findings suggest that the number of DAT binding sites is higher in drug-naive patients suffering from ADHD than in normal controls. The decrease in available DAT binding sites under treatment with methylphenidate correlates well with the improvement in clinical symptoms. The data of this study help to elucidate the complex dysregulation of the dopaminergic neurotransmitter system in patients suffering from ADHD and the effect of treatment with psychoactive drugs.

Adult↗
PubMed2000

[Prognostic value of hepatobiliary functional scintigraphy in diagnosis and after-care of biliary atresia].

AIM: To investigate the prognostic relevance of hepatobiliary scintigraphy (HBS) in newborns suffering from biliary atresia (BA) for establishing the primary diagnosis and in the postoperative follow-up after portoenterostomy (Kasai). METHODS: Twenty newborns with direct hyperbilirubinemia and 6 children after operative treatment of BA (Kasai) underwent HBS with Tc-99m-DEIDA. In patients without intestinal drainage, hepatocellular extraction was estimated visually and calculated semiquantitatively by means of liver/heart-ratio 5 min p.i. RESULTS: 10/20 patients with hyperbilirubinemia did not display biliary drainage; 6 had BA, 3 intrahepatic hypoplasia, and one showed a bile plug syndrome. 4/6 with BA but none of the 4 children with diagnoses other than BA presented with a good extraction. All of the 4 children with BA, who had either pre- or postoperatively a bad extraction, needed liver transplantation due to liver failure. Both of the two newborns with BA and favourable outcome after Kasai had a good extraction in the preoperative HBS and demonstrated good intestinal drainage in the postoperative scan. CONCLUSION: HBS rules out BA with high accuracy by demonstrating drainage of bile into the intestine. In newborns without drainage a good extraction favours the diagnosis of BA. In newborns with BA a bad extraction seems to indicate a poor postoperative prognosis after Kasai operation. HBS might therefore help to select those children who will not benefit from portoenterostomy. Postoperatively, HBS can easily and quickly confirm the successful hepatobiliary anastomosis by demonstrating biliary drainage into the intestine.

Biliary Atresia↗
PubMed2000

D2 receptor occupancy under recommended and high doses of olanzapine: an iodine-123-iodobenzamide SPECT study.

The aim of this study was to compare the degree of striatal dopamine D2 receptor availability in patients treated with recommended (5-20 mg, mean dose 11.9 +/- 6.3 mg daily) and higher doses (25-40 mg, mean 32.1 +/- 5.6 mg daily) of the novel antipsychotic drug olanzapine by means of [123I] IBZM Single photon emission computed tomography (SPECT). The results were compared to those of a group of 10 untreated, healthy, age- and sex-matched controls. The degree of dopamine D2 receptor occupancy in the patient group was correlated with the presence of extrapyramidal symptoms (EPS). A total of 20 patients who met the DSM III R criteria for schizophrenia or schizoaffective disorder received a clinically effective antipsychotic monotherapy with olanzapine. The mean daily dose of olanzapine ranged from 0.05-0.6 mg/kg body weight. The dopamine D2 receptor binding was reduced in all patients treated with olanzapine. Specific IBZM binding expressed as the [STR-BKG]/BKG ratio ranged from 0.13-0.61 (healthy controls 0.95). The D2 receptor availability revealed an exponential dose-response relationship (r = - 0.85, p < 0.001). The frequency of EPS induced by olanzapine was considerably lower. Only one patient, treated with 40 mg olanzapine, suffered from severe EPS symptoms and had to be given biperiden. There were no significant differences in the presence of EPS symptoms between patients with recommended doses and those with higher doses of olanzapine.

Adult↗
PubMed2000

PET and SPECT findings in alcohol hallucinosis: case report and super-brief review of the pathophysiology of this syndrome.

Alcohol hallucinosis is a rare complication of chronic alcoholism with schizophreniform symptomatology. The pathophysiology is basically unclear. We report the case of a 48-year-old, never-medicated, long-term alcoholic suffering from alcohol hallucinosis with pure acoustic hallucinations for at least six months. Current FDG PET data suggest a hypofrontality and possibly a thalamic hypofunction in alcohol hallucinosis, findings similar to those reported in unmedicated schizophrenics. Current IBZM SPECT data do not support a dopamine receptor dysfunction in alcohol hallucinosis but TRODAT SPECT showed reduced dopamine transporter binding. Possible implications of these findings are discussed.

Alcoholism↗